SANTA CLARA – Jim Harbaugh had Doug Baldwin on the line and let him get away.

On the final day of the draft in April, Harbaugh dialed Baldwin, one of his wide receivers at Stanford, and told him the 49ers weren't going to select him. Instead he said they were interested in signing him as a free agent when the lockout ended.

It's one of the few personnel miscalculations Harbaugh and the 49ers' front office have made this year.

Baldwin signed with Seattle instead, and he not only landed a spot on the Seahawks final roster, he has emerged as their top receiver.

He has 46 catches for 731 yards and three touchdowns, including a 55-yard score against the 49ers in Week 1. He's on pace to become the first undrafted rookie to lead his team in receptions and receiving yards since Bill Groman of the Houston Oilers in 1960.

Baldwin missed practice Thursday with an ankle injury, but he's expected to play against the 49ers on Saturday in Seattle.

Among rookies, Baldwin trails only Cincinnati's A.J. Green, Baltimore's Torrey Smith and Atlanta's Julio Jones in receiving yards. Green and Jones were picked in the first round; Smith went in the second.

Wide receiver, meanwhile, is perhaps the 49ers' most threadbare position, due in part to injuries. Michael Crabtree and Braylon Edwards have missed games this season, and Ted Ginn might sit out Saturday's game after spraining an ankle Monday.

Josh Morgan was lost for the season after breaking his leg on Oct. 9, forcing the 49ers to sign free agent Brett Swain.

The team also could be thin at the position heading into the offseason. Only Crabtree and Kyle Williams are signed beyond this season. The 49ers used a sixth-round draft pick on USC's Ronald Johnson in April, but he struggled in training camp and didn't even make the practice squad.

"We should have drafted Doug," Harbaugh said this week.

Asked why that didn't happen and why the 49ers couldn't land Baldwin as a free agent, Baldwin said, "I have no idea.

"I guess it's just the way it played out," Baldwin said on a conference call. "They already had a pretty stacked roster at wide receiver, and I felt they were kind of set at that position at the time. So I felt like Seattle was the best opportunity for me to come in and win the job."

Buddy Baker, Baldwin's agent, said more than a dozen teams, including the 49ers, were interested in the 5-foot-10, 189-pound wideout when free agency began. But he said a handful of teams – Seattle, Cleveland and San Diego – were more intent than the others.

Seattle offered a $17,500 signing bonus, one of the highest for any undrafted player this year.

Baker said that helped Seattle's cause but wasn't the determining factor.

"Doug's a mature, intelligent player," Baker said. "He was going to go where he thought he had the best opportunity. And it's worked out that way."

Baldwin had perhaps his best all-around game of the season earlier this month when he scored on a 29-yard pass and blocked a punt that was returned for a touchdown in a win over St. Louis on "Monday Night Football."

Seattle coach Pete Carroll said the Seahawks knew Baldwin could play, but he admitted they didn't think he'd be their top receiver after 15 games.

"We had to fight a bunch of teams that wanted him," Carroll said. "He's been a really, really exciting young player, not just catching the ball, but he's been good on special teams as well and contributing in any way that we've asked him."

What separates Baldwin is his competitiveness, which only ramped up when he went undrafted, Carroll said.

"Oh, I would think that that's worked for him – yeah," he said. " … Those kinds of guys are looking for a reason. They gave him a big reason. He's passed a lot of guys' expectations and probably a lot of output from a lot of the players that were drafted much higher than him."

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